8-digit numbers are formed using the digits 1, 1, 2, 2,2,3,4,4 . The number of such numbers in which the odd digits do no occupy odd places, is:

Step-by-step solution

In 8 digits numbers, 4 places are odd places. Also, in the given 8 digits, there are three odd digits 1,1 and 3. No. of ways three odd digits arranged at four even places = 4 P₃ 2 ! = 4 ! 2 ! No. of ways the remaining five digits 2 , 2, 2, 4 and 4 arranged at remaining five places = 5 ! 3 ! 2 ! Hence, required number of 8 digits number = 4 ! 2 ! 5 ! 3 ! 2 ! =120